Harry Potter's Half Sister
by Violentpixie
Summary: Imagine how Harry Potter felt when he discovers his half-sister who is Lilys & Snapes. Now coping with the family she craved for Rose Evans must deal with an age old prophecy plus wondering how to get Draco Malfoy to ask her out HPGW HGRW OCDM
1. Prologue 01

**Prologue**

It was a dark and stormy night, the wind battering against the window as a cloaked figure fled that lonely home in Godric's Hollow. Baby's screams echoed across the night and yet nobody was there. Nobody was listening.

The cloaked man dissapeared. It might have been aparation but, to any passing muggles by, it would look like the man had dissapeared into thin air.

And somebody else aparated to the scene, running towards the house, praying it wasn't too late. He hoped beyond hope that what Lily told him hadn't been true, that Peter had not betrayed his friends. But even as he walked up the path and heard the screaming, he knew it was too late. He entered the home and from the inside it definitly looked broken into. There was blood...and it led to a body.

Snape sharply inhaled a take of breath as he saw his deepest enemies body lying dead on the floor, his eyes glazed over, glasses askew and cracked. Snape cast it only one look before running to the sceaming. Surely once the Dark Load Voldermort entered a house with a mind to kill, there was nobody left to scream.

And that's when he saw it. Her perfectly glorious self, dead. Her face contorted in pain that did not suit her angelic features, red hair surrounding her head like a halo. Severus could not bare to look at her in so much agony. He leant over and closed her eyes, fighting his own tears.

And then the screaming got louder. Severus swiftly walked into the other room and saw a child. Her child. Her's and James'. The boy was crying his eyes out, a thin lightning bolt scar on his forehead.

And so Severus searched for the letter that Lily wrote to him, like she promised, it was under the child's pillow.

_Dear Severus, My best friend_

_This letter is being sent to you from beyond the grave._

_Voldermort knows where we are hidden and he is comming for us._

_Dumbledor spoke of a prophecy and so most likely my Harry is alive._

_If he is then promise to me, the girl whom you love that you will keep him safe._

_If he is not, then look after my daughter._

_I cannot reveal her whereabouts as this letter may be found by another._

_She cannot be harmed otherwize Harry will die for there was another prophecy._

_One concering my daughter... _Our _daughter._

_Please Severus, find her. Her name is Rose Eileen Snape-Evans and she is two currently.  
_

_Keep her and her half-brother safe._

_Love Lily xxx_

Severus started hyperventalating. The boy was alive, meaning that the crazy woman Sybil had been right. This boy, Harry Potter, had survived and if he sucseded in killing Lord Voldermort, he would become the most famous wizard of all time. But what the prophecy had not guessed at was the possibility of another one with the power. This girl, Rose Evans. Born out of wedlock, a secret, his daughter. He had no doubt that this girl would become a powerful witch, maybe even a sorceress, what will Lily's intelligance and his power.

Snape gave Harry one last look and noted that the boys eyes were brilliant green and almond shaped.

Severus placed the letter and a photo of Lily from the mantle piece intop his pocket as he heard a motorbike's engine before he aparated and dissapeared into the night filled with the crying of a young boy.


	2. Prologue 02

**Prologue 0.2  
**

Severus drained another glass of Firewhiskey that Rosmerta ad given every member of the Staff at Howarts last Christmas. He stared at the photo of the woman he loved, never fully accepting that she was dead...and that it was all his fault. He had told Voldermort about the prophecy and he had concluded that it had been Lily's and James' son. It was all his fault. Severus vowed to himself that he would do whatever it took to kill Voldermort, even if it meant grovelling to Albus, to confess to everything.

Severus filled another glass as he read through the letter again. He had a daughter who was out there somewhere. Severus slightly resented Lily for not telling him about her or where she was but that feeling dissapeard when he remembered that she was dead and that he loved her.

* * *

_"I cannot believe you agreed to go on a date with him, Lily." Severus was appauled. He rememberd when they use to joke about it._

_'I am so going to fail my Potions OWL.' 'No Sev. You'll fail when i say yes to Potter' And then they would laugh and then start saying how utterly irritating his 'stalker' status had become._

_"It's not a date." Lily Evans sighed. "He asked to accompany me to Hogsmeade. I would go with you if you asked." She said and red filled the cheeks of Severus._

_"It sound like a date." He mumbled. "But seriously Evans. Potter? Why? It's like me going out with Bellatrix."_

_Lily laughed. "That would be funny. But Rodolphus asked Bellatrix so you're out of luck, Sev."_

_"Stop changing the subject Evans." _

_"Fine, Snape." She teased. "Ja- Potter. Well, he's matured alot over the summer. Anyway, it's not like i'm going to marry him"_

_"Potter, mature? Doubt that the words even in his vocabulary."_

_

* * *

_

_"What!" Severus shouted. "It's unbelieveable enough that you've been his girlfirend for this long. I honestly didn't expect him to be good enough for you. But now you're marrying him?"_

_"Please Severus. Please come."_

_"What? And be your bridesmaid?" He sneered._

_"Well, if you're going to make a joke of it. I'll ask Molly and Alice." Lilly's usuall smile had gone. "I don't really know Auther and Frank that well but aparently they're really nice." _

_"Please, Lils. See sense." Severus pleaded._

_"No." She said, ever stubborn. "No i won't. Just because you have a grudge against him does not mean that you can insult him."_

_"A grudge? If you remember, he was an atagonising pain in the rear who constantly made my lif practically hell."_

_"You're just being silly Severus. Fine then. Don't come." Lilly turned away from him, tears prickeling at her eyes. "See if i care."_

_

* * *

_

_"And do you, Lilly Evans, take James Potter to be your lawfully wedded husband, in sickness and in health, for richer and for poorer, until death do you part?"_

_"I do." Lilly smiled._

_"Then by the magical bonds that entwine you, i pronounce you husband and wife. You may now-"_

_But before the man had a chance to speak, Lilly threw her arms around James' neck and pressed her lips on his, tears spilling down her cheeks, a magnificent smile on her lips. Molly, Alice, Sirius and Remus were grinning like crazy. _

_The party afterwards was a great story. Sirius flirting with Alice and Frank hexing him so he spoke backwards. Arther popping the question to Molly Prewett. Petunia trying desperatly not to be seen, sneaking to say congratulations to her sister and boast about being pregnant before leaving as quickly as possible._

_But Severus did not enjoy these festivities and Lilly choked back a sob when she realised he hadn't come._

_And Severus Snape who had watched, invisible, as the girl he loved kissed the man he hated as she wed him. He had never cried since his childhood but this was as close he had ever gotten to it._

_

* * *

_

Severus drained another glass when he remembered what happened after this. James had gotten really drunk at Sirius' birthday party and had made out with a pretty blonde before collapsing. It turns out later that the blonde girl had spiked his drink with Ammoria but Lilly did not know this.

She had stormed from the party, crying. But she had turned up at her best friend's house, hoping that he could reasure her like he use to before she had 'betrayed' him by marrying Potter.

Then things happened and after that, Severus did not have any contact from her for two years. But after that two years, the most horrible meeting between them occured.

_

* * *

_

_"Lilly. What is it?" Severus put his wand away when he saw who it was that had been hammering so much on his door._

_"Severus. They're comming for me." She bit her bottom lip, tears streaming down her face, smudging her make-up._

_"What do you mean? Who?" Snape asked._

_"The Death Eaters. V-voldermort found a prophecy and he thinks it's about Harry."  
_

_"Harry?" Snape said._

_"My Harry, my baby." She sobbed. _

_"What about the Death Eaters?" Severus asked, trying to calm down as him freaking out would hardly help Lilly stop talking incoherently._

_"A prophecy. One of the Death Eater's found out about one and Voldermort thinks it's about my son."_

_Lilly had a son. Snape tried to not let this information disturb him but it did. But then he realised. What had he done? That bat Sybil talking about the boy who could kill Voldermort. Riddle thought the child was Lilly's son. All his fault..._

_"Calm down, Lilly." Snape said._

_"I can't Sev. I'm going to die and so is James. And little Harry." She sniffed. "I'm sorry Severus, i cannot stay long but i need you to do something for me. When i die,"_

_"If you die." Severus interupted._

_"WHEN i die," she continued. "Please look under Harry's pillow. It's a letter. Very important." She turned to leave before saying one, very confusing thing. "Don't blame padfoot." Before running out of the front door_

_

* * *

_

Severus stood up and flourished his wand. "Expecto Patronum" he whispered and the doe leaped from his wand.

"Tell Albus that i need to speak to him again." Snape said. The doe nodded before leaping away.


End file.
